A missing listing does not mean out of network. Directories change, and a listing does not cover every office. Call Dr. Chafen’s office at (925) 296-7150 to confirm they take your plan. Ask about the office you use, its medical group, referrals and appointments.
Plans whose provider directory lists this clinician
Licensed to practise in California · since 1970 · expires 2027-11-30 · Loma Linda University School of Medicine.
No disciplinary actions, convictions, malpractice judgments or citations in this record.
School, training and certification
What this clinician told their state board, medical school and everything before it. Only some states publish this, so nothing here means the state does not say, not that there was no training or certification.
Specialty certification
American Board of Nuclear Medicine - Nuclear Medicine
American Board of Radiology - Diagnostic Radiology
Original Medicare doctor bills
$48,149
Medicare paid this office $48,149 for 857 people.
This is what Medicare paid the clinician — not Medicare Advantage, and not the pharmacy.
Largest Original Medicare bills
Screening mammography
270
$11,660
$43
Screening mammography
217
$9,366
$43
Screening 3d breast mammography
250
$8,480
$34
Screening 3d breast mammography
133
$4,508
$34
Dxa bone density measurement of hip, pelvis, spine
262
$2,955
$11
See all 10 services
Every Original Medicare service billed
Screening mammography
270
$11,660
$43
Screening mammography
217
$9,366
$43
Screening 3d breast mammography
250
$8,480
$34
Screening 3d breast mammography
133
$4,508
$34
Dxa bone density measurement of hip, pelvis, spine
262
$2,955
$11
Diagnostic mammography of both breasts
61
$2,396
$39
Diagnostic digital breast tomosynthesis, unilateral or bilateral (list separately in addition to 77065 or 77066)
92
$2,303
$25
Limited ultrasound scan of 1 breast
65
$2,130
$32
Diagnostic mammography of 1 breast
57
$2,025
$35
Biopsy of breast and placement of locating device using ultrasound, first growth
11
$1,574
$143
Procedures year by year
Procedures billed to Original Medicare by year
Procedure
2019
2020
2021
2022
2023
2024
Biopsy of breast and placement of locating device using ultrasound, first growth
42
20
17
14
17
11
Times billed to Original Medicare each year. A blank year means fewer than 11 people had it, or none: Medicare does not publish smaller counts. Medicare Advantage patients are not included.
Who their Medicare patients are
857 Original Medicare patients in 2024. Average age 73 · Under 65 5% · 85 and older 5% · Women 98% · Also on Medicaid 34% · Health risk score 0.82. At or below the middle of the specialty; the typical diagnostic radiology clinician is at 1.7.
The office billed $208,645, Medicare allowed $51,563 and paid $48,149; for 1,441 services of 16 kinds.
Original Medicare patients only. A risk score of 1.0 is the average Medicare patient; higher means sicker. Any count under 11 is hidden.
Year by year
Original Medicare by year
2024
857
1,441
73
0.82
$208,645
$48,149
2023
1,256
2,048
73
0.77
$304,420
$68,432
2022
1,053
1,603
73
0.77
$243,621
$53,247
2021
1,317
1,826
72
0.80
$271,670
$61,558
2020
721
962
72
0.86
$156,555
$35,017
2019
2,116
2,725
72
0.86
$423,313
$96,497
2018
1,844
2,258
72
0.95
$346,293
$77,237
2017
2,274
2,691
72
0.96
$411,133
$86,157
2016
2,237
4,419
71
0.90
$425,303
$90,719
2015
2,538
5,082
71
0.90
$490,521
$107,908
2014
2,136
4,294
71
0.92
$364,621
$87,512
2013
2,372
4,696
72
1.08
$396,358
$93,677
Original Medicare only. A service billed for fewer than 11 people in a year is hidden, so the lines can add up to less than the year's total.
See the services billed each year
2023: 10 services
Original Medicare services billed in 2023
Screening mammography
382
$15,906
$42
Screening mammography
357
$14,865
$42
Screening 3d breast mammography
273
$8,998
$33
Screening 3d breast mammography
156
$5,142
$33
Diagnostic mammography of both breasts
113
$4,860
$43
Diagnostic digital breast tomosynthesis, unilateral or bilateral (list separately in addition to 77065 or 77066)
172
$4,457
$26
Limited ultrasound scan of 1 breast
123
$3,715
$30
Dxa bone density measurement of hip, pelvis, spine
328
$3,536
$11
Diagnostic mammography of 1 breast
94
$3,246
$34
Biopsy of breast and placement of locating device using ultrasound, first growth
17
$2,326
$137
2022: 10 services
Original Medicare services billed in 2022
Screening mammography
320
$13,344
$42
Screening mammography
293
$12,197
$42
Screening 3d breast mammography
132
$4,390
$33
Diagnostic mammography of both breasts
102
$4,193
$41
Diagnostic digital breast tomosynthesis, unilateral or bilateral (list separately in addition to 77065 or 77066)
160
$3,805
$23
Diagnostic mammography of 1 breast
93
$3,077
$32
Dxa bone density measurement of hip, pelvis, spine
273
$2,980
$11
Limited ultrasound scan of 1 breast
96
$2,872
$29
Screening 3d breast mammography
86
$2,869
$33
Biopsy of breast and placement of locating device using ultrasound, first growth
14
$1,940
$139
2021: 11 services
Original Medicare services billed in 2021
Screening mammography
405
$17,391
$43
Screening mammography
347
$14,900
$43
Diagnostic mammography of both breasts
103
$4,439
$43
Dxa bone density measurement of hip, pelvis, spine
388
$4,294
$11
Diagnostic mammography of 1 breast
108
$3,910
$35
Limited ultrasound scan of 1 breast
116
$3,783
$29
Diagnostic digital breast tomosynthesis, unilateral or bilateral (list separately in addition to 77065 or 77066)
145
$3,741
$25
Screening 3d breast mammography
71
$2,413
$34
Biopsy of breast and placement of locating device using ultrasound, first growth
17
$2,258
$133
Screening 3d breast mammography
62
$2,107
$34
Dxa bone density measurement of forearm, finger, hand, or foot
11
$127
$12
2020: 10 services
Original Medicare services billed in 2020
Screening mammography
233
$10,224
$44
Screening mammography
199
$8,749
$44
Biopsy of breast and placement of locating device using ultrasound, first growth
19
$2,897
$145
Diagnostic mammography of both breasts
64
$2,848
$45
Dxa bone density measurement of hip, pelvis, spine
199
$2,256
$11
Diagnostic digital breast tomosynthesis, unilateral or bilateral (list separately in addition to 77065 or 77066)
78
$2,072
$27
Diagnostic mammography of 1 breast
49
$1,833
$37
Limited ultrasound scan of 1 breast
46
$1,395
$28
Screening 3d breast mammography
27
$932
$35
Screening 3d breast mammography
25
$863
$35
2019: 11 services
Original Medicare services billed in 2019
Screening mammography
732
$31,513
$43
Screening mammography
541
$23,290
$43
Diagnostic mammography of both breasts
161
$7,289
$45
Dxa bone density measurement of hip, pelvis, spine
590
$6,573
$11
Diagnostic mammography of 1 breast
161
$5,999
$36
Biopsy of breast and placement of locating device using ultrasound, first growth
41
$5,900
$140
Diagnostic digital breast tomosynthesis, unilateral or bilateral (list separately in addition to 77065 or 77066)
193
$5,255
$27
Limited ultrasound scan of 1 breast
132
$4,399
$30
Screening 3d breast mammography
59
$2,001
$34
Screening 3d breast mammography
47
$1,594
$34
Dxa bone density measurement of hip, pelvis, spine including spine fracture assessment
18
$307
$17
2018: 10 services
Original Medicare services billed in 2018
Screening mammography
662
$28,135
$43
Screening mammography
384
$16,320
$43
Diagnostic mammography of both breasts
163
$6,864
$42
Dxa bone density measurement of hip, pelvis, spine
484
$5,548
$11
Diagnostic mammography of 1 breast
163
$5,509
$32
Biopsy of breast and placement of locating device using ultrasound, first growth
30
$4,175
$139
Limited ultrasound scan of 1 breast
136
$3,984
$27
Diagnostic digital breast tomosynthesis, unilateral or bilateral (list separately in addition to 77065 or 77066)
114
$2,840
$25
Screening 3d breast mammography
36
$1,206
$33
Dxa bone density measurement of hip, pelvis, spine including spine fracture assessment
38
$421
$11
2017: 9 services
Original Medicare services billed in 2017
Screening mammography, bilateral (2-view study of each breast), including computer-aided detection (cad) when performed
1,356
$51,704
$38
Diagnostic mammography, including computer-aided detection (cad) when performed; bilateral
204
$7,828
$38
Dxa bone density measurement of hip, pelvis, spine
622
$6,618
$11
Diagnostic mammography, including computer-aided detection (cad) when performed; unilateral
171
$5,439
$30
Biopsy of breast and placement of locating device using ultrasound, first growth
35
$4,596
$131
Limited ultrasound scan of 1 breast
158
$4,575
$27
Biopsy of breast and placement of locating device using x-ray with needle, first growth
18
$2,509
$139
Diagnostic digital breast tomosynthesis, unilateral or bilateral (list separately in addition to 77065 or 77066)
56
$1,377
$25
Screening 3d breast mammography
21
$661
$31
2016: 12 services
Original Medicare services billed in 2016
Screening mammography, bilateral (2-view study of each breast), including computer-aided detection (cad) when performed
1,290
$47,717
$37
Diagnostic mammography, including computer-aided detection (cad) when performed; bilateral
209
$7,323
$35
Diagnostic mammography, including computer-aided detection (cad) when performed; unilateral
212
$6,259
$28
Screening mammography, bilateral (2-view study of each breast), including computer-aided detection (cad) when performed
164
$6,066
$37
Biopsy of breast and placement of locating device using ultrasound, first growth
42
$5,654
$135
Limited ultrasound scan of 1 breast
166
$4,936
$28
Dxa bone density measurement of hip, pelvis, spine
412
$4,511
$11
Computer analysis of screening mammogram to assist detection of cancer
1,290
$3,947
$3
Biopsy of breast and placement of locating device using x-ray with needle, first growth
12
$1,719
$143
Computer analysis of diagnostic mammogram
365
$860
$2
Computer analysis of screening mammogram to assist detection of cancer
164
$502
$3
Dxa bone density measurement of hip, pelvis, spine including spine fracture assessment
27
$290
$11
2015: 12 services
Original Medicare services billed in 2015
Screening mammography, bilateral (2-view study of each breast), including computer-aided detection (cad) when performed
1,699
$64,169
$38
Diagnostic mammography, including computer-aided detection (cad) when performed; bilateral
261
$9,299
$36
Biopsy of breast and placement of locating device using ultrasound, first growth
47
$6,577
$140
Diagnostic mammography, including computer-aided detection (cad) when performed; unilateral
223
$6,557
$28
Computer analysis of screening mammogram to assist detection of cancer
1,698
$5,567
$3
Limited ultrasound scan of 1 breast
175
$5,416
$29
Dxa bone density measurement of hip, pelvis, spine
365
$4,070
$11
Biopsy of breast and placement of locating device using x-ray with needle, first growth
18
$2,509
$139
Screening mammography, bilateral (2-view study of each breast), including computer-aided detection (cad) when performed
42
$1,591
$38
Computer analysis of diagnostic mammogram
445
$1,116
$2
Dxa bone density measurement of hip, pelvis, spine including spine fracture assessment
26
$310
$12
Computer analysis of screening mammogram to assist detection of cancer
42
$138
$3
2014: 11 services
Original Medicare services billed in 2014
Screening mammography, bilateral (2-view study of each breast), including computer-aided detection (cad) when performed
1,560
$58,902
$38
Diagnostic mammography, including computer-aided detection (cad) when performed; bilateral
165
$5,583
$34
Computer analysis of screening mammogram to assist detection of cancer
1,560
$5,117
$3
Biopsy of breast and placement of locating device using ultrasound, first growth
33
$4,498
$136
Diagnostic mammography, including computer-aided detection (cad) when performed; unilateral
132
$3,606
$27
Dxa bone density measurement of hip, pelvis, spine
302
$3,360
$11
Ultrasound of breasts
141
$2,856
$20
Computer analysis of diagnostic mammogram
278
$654
$2
X-ray of chest, 1 view, front
39
$295
$7
Spine scanning X-ray done with bone density measurement for spine compression
19
$123
$6
X-ray of surgical specimen
14
$91
$7
2013: 15 services
Original Medicare services billed in 2013
Screening mammography, bilateral (2-view study of each breast), including computer-aided detection (cad) when performed
1,776
$65,738
$37
Biopsy of breast using imaging guidance
38
$6,192
$151
Computer analysis of screening mammogram to assist detection of cancer
1,780
$5,592
$3
Diagnostic mammography, including computer-aided detection (cad) when performed; bilateral
138
$4,423
$32
Ultrasound of breasts
116
$2,266
$19
Diagnostic mammography, including computer-aided detection (cad) when performed; unilateral
87
$2,097
$24
X-ray of chest, 1 view, front
215
$1,785
$7
Ultrasonic guidance for needle placement
33
$1,062
$28
Radiological supervision and interpretation of imaging guidance for breast biopsy or insertion of needle
12
$792
$66
Dxa bone density measurement of hip, pelvis, spine
73
$774
$11
Computer analysis of diagnostic mammogram
223
$467
$2
X-ray of chest, 2 views, front and side
36
$246
$7
X-ray of surgical specimen
26
$194
$7
X-ray of chest, special views
21
$153
$7
Spine scanning X-ray done with bone density measurement for spine compression
20
$118
$6
Medicaid work
$3,411 in 2024
Medicaid paid $3,411 for 671 billed services this clinician did in 2024, up to 51 people in a month for one service.
Medicaid and CHIP claims where this clinician did the service, fee-for-service and managed care together. Any month with fewer than 11 patients is hidden, so small Medicaid practices undercount.
Largest Medicaid services in 2024
Screening mammography, bilateral (2-view study of each breast), including computer-aided detection (CAD) when performed
213
$972
SCREENING DIGITAL BREAST TOMOSYNTHESIS BI
206
$763
Ultrasound, breast, unilateral, real time with image documentation, including axilla when performed; limited
84
$495
Diagnostic digital breast tomosynthesis, unilateral or bilateral (list separately in addition to 77065 or 77066)
108
$476
DIAGNOSTIC MAMMOGRAPHY COMPUTER-AIDED DETCJ BI
46
$453
DIAGNOSTIC MAMMOGRAPHY COMPUTER-AIDED DETCJ UNI
14
$252
Medicaid work by year
2024
671
6
51
$3,411
2023
977
6
42
$5,473
2022
462
5
36
$2,177
2021
504
7
55
$2,650
2020
229
6
37
$1,480
2019
1,077
6
72
$7,272
2018
717
4
73
$4,432
See the largest Medicaid services in earlier years
2023
Largest Medicaid services in 2023
Screening mammography, bilateral (2-view study of each breast), including computer-aided detection (CAD) when performed
301
$1,609
Ultrasound, breast, unilateral, real time with image documentation, including axilla when performed; limited
165
$1,235
SCREENING DIGITAL BREAST TOMOSYNTHESIS BI
262
$1,084
DIAGNOSTIC MAMMOGRAPHY COMPUTER-AIDED DETCJ BI
82
$799
Diagnostic digital breast tomosynthesis, unilateral or bilateral (list separately in addition to 77065 or 77066)
152
$735
DXA BONE DENSITY STUDY 1/> SITES AXIAL SKEL
15
$11
2022
Largest Medicaid services in 2022
Screening mammography, bilateral (2-view study of each breast), including computer-aided detection (CAD) when performed
206
$1,038
Ultrasound, breast, unilateral, real time with image documentation, including axilla when performed; limited
86
$485
Diagnostic digital breast tomosynthesis, unilateral or bilateral (list separately in addition to 77065 or 77066)
76
$368
SCREENING DIGITAL BREAST TOMOSYNTHESIS BI
81
$232
DIAGNOSTIC MAMMOGRAPHY COMPUTER-AIDED DETCJ BI
13
$55
2021
Largest Medicaid services in 2021
Screening mammography, bilateral (2-view study of each breast), including computer-aided detection (CAD) when performed
279
$1,248
Ultrasound, breast, unilateral, real time with image documentation, including axilla when performed; limited
61
$453
Diagnostic digital breast tomosynthesis, unilateral or bilateral (list separately in addition to 77065 or 77066)
62
$403
DIAGNOSTIC MAMMOGRAPHY COMPUTER-AIDED DETCJ UNI
33
$282
DIAGNOSTIC MAMMOGRAPHY COMPUTER-AIDED DETCJ BI
22
$223
SCREENING DIGITAL BREAST TOMOSYNTHESIS BI
33
$33
DXA BONE DENSITY STUDY 1/> SITES AXIAL SKEL
14
$8
2020
Largest Medicaid services in 2020
Screening mammography, bilateral (2-view study of each breast), including computer-aided detection (CAD) when performed
110
$729
Ultrasound, breast, unilateral, real time with image documentation, including axilla when performed; limited
38
$306
DIAGNOSTIC MAMMOGRAPHY COMPUTER-AIDED DETCJ BI
13
$251
Diagnostic digital breast tomosynthesis, unilateral or bilateral (list separately in addition to 77065 or 77066)
43
$178
DIAGNOSTIC MAMMOGRAPHY COMPUTER-AIDED DETCJ UNI
12
$9
DXA BONE DENSITY STUDY 1/> SITES AXIAL SKEL
13
$8
2019
Largest Medicaid services in 2019
Screening mammography, bilateral (2-view study of each breast), including computer-aided detection (CAD) when performed
585
$4,011
Ultrasound, breast, unilateral, real time with image documentation, including axilla when performed; limited
155
$1,104
DIAGNOSTIC MAMMOGRAPHY COMPUTER-AIDED DETCJ BI
90
$1,050
Diagnostic digital breast tomosynthesis, unilateral or bilateral (list separately in addition to 77065 or 77066)
145
$634
DIAGNOSTIC MAMMOGRAPHY COMPUTER-AIDED DETCJ UNI
88
$472
DXA BONE DENSITY STUDY 1/> SITES AXIAL SKEL
14
$0
2018
Largest Medicaid services in 2018
Screening mammography, bilateral (2-view study of each breast), including computer-aided detection (CAD) when performed
511
$3,271
Ultrasound, breast, unilateral, real time with image documentation, including axilla when performed; limited
134
$806
DIAGNOSTIC MAMMOGRAPHY COMPUTER-AIDED DETCJ BI
58
$319
DXA BONE DENSITY STUDY 1/> SITES AXIAL SKEL
14
$35
Checkups this office reported
Medicare did not publish checkup rates for this clinician.
Medicare’s overall office score
90.8 / 100
Scores the office’s reporting and systems. It is not a grade for how the doctor treats you.
Professional record
NPI
1336131689
Licence
CA G17994California G17994: Current · expires 2027-11-30
More record details
Sole proprietor
No
Taxonomy
Diagnostic radiology (2085R0202X)
Mailing address
2125 Oak Grove Rd, #200, Walnut Creek, CA, 94598
NPI first listed
2005-08-22
NPI last updated
2015-04-02
This is when the NPI record was last certified, not a medical board exam.